Meaning of C-4 (CONTROLLED COLLAPSE CHIP CONNECTION) in English

C-4 (CONTROLLED COLLAPSE CHIP CONNECTION)

A solder joint connecting a substrate directly to an IC in a flip chip configuration. In this packaging scheme, a solder ball is formed on the IC, the IC is placed active circuitry down onto a substrate, and the solder is reflowed. As the solder melts, the solder balls collapse into a shape controlled by the surface tension of the liquid solder while supporting the weight of the IC.